Objective

This project began with a goal to investigate use of QSI's Titan decoder with S-CAB radio and battery power. It evolved into a project to install Titan decoders in S-scale brass locos using BPS battery power and controlled by S-CAB radio.

QSI's trademarks and intellectual property rights are acknowledged.

The purpose of this post is to publish some videos showing progress toward our objective. I say "our objective" because this has been a cooperative effort with an S-CAB user, whom I will call "Bill". It is work in progress and these videos, taken on my workbench using a cell phone, are not intended to be sophisticated little movies.

Background

Until now, a search of this S-CAB website for "Titan" (use the search box at top of the page) produces an obscure reference on the Price List page. It has remained obscure because there's not much demand for Titan. However, Bill has persisted with great patience and tenacity. It began mid-2011, when he noticed QSI was replacing their then-current sound decoder (Revolution) with a new product called "Titan".

Bill purchased and sent Titan to me as soon QSI began delivery. By July, 2011, with some help from QSI, I converted Titan for use with S-CAB and battery power. This decoder is a very ambitious product; both in terms of functionality and technical complexity, which makes it difficult, both for me as I work on S-CAB radio control and battery power, but also for users trying to install the product. I thought it premature at this early date to publicize S-CAB compatibility. I had no experience installing or operating a loco with Titan. Bill was busy testing S-CAB (with Tsunami) and BPS power in one of his locos and did not follow up immediately with a Titan order.

However, an order for S-CAB with Titan did come through Northwest Short Line (NWSL) from a purchaser with computer programming experience. I mention this because this client dragged me reluctantly into providing S-CAB support for programming Titan CVs. With professional programming experience, he did not require me to get involved with actual programming of Titan CVs. Consequently, I was not well-prepared for the full scope of a Titan installation.

Fact is, Titan does not distinguish itself from the crowd until its CVs are well-tuned to the characteristics of a loco. In other words, making Titan compatible with S-CAB and installing it in a loco with radio control and battery power is only the first half of the challenge. Completing the battle requires diligent work programming CVs, a process that requires QSI's Quantum Programmer connected to a PC running their CV Manager software.

﻿In theory, Titan can be programmed without a computer, but it's practically impossible without the capability to both read and write CV values. Without the ability to read a CV value, each change must be documented manually during a trail and error process to refine decoder behavior.﻿

Eventually, Bill placed an order for Titan installation in his locos and we have been working on this for over a year. It has become a journey, and it goes on, with Bill testing locos on his layout and learning how to program CVs while I kept trying to debug Titan's strange behavior. I'm now cautiously optimistic that we have reached an important milestone of realistic loco operation. Bill has been generous with his support as well as periodic reminders to get on with it. I've produced material during this project to write several blog posts (and I might do that) but we need to refresh our motivation with a little show and tell.

Let's See Some Action

In each of the following videos, Bill's loco is operating with BPS battery power. No power is connected to the rails. A Titan decoder is controlling the loco in response to operator commands transmitted by radio directly from the S-CAB throttle to a radio receiver in the loco. All loco system components, including BPS and battery, are installed in the tender. An S-CAB throttle is the only other device used in these videos (excluding my cell phone).

Above Demo 2. WhistleHere, I sound the whistle and, if you listen carefully, you'll hear brakes applied at the end of run.

Above Demo 4. BrakingHere, a newbie engineer backs up too fast, misjudges end of track and is hard on the brakes.

Left Demo 1. Speed ControlThis video shows decoder control of acceleration and deceleration. I use the throttle only twice. First, I move the throttle to full speed to begin the run. Since I have only 6 feet of track to work with, the loco does not reach full speed before I move the throttle to zero so that the loco can slow normally and safely stop without additional braking. After a little practice, sure enough, the loco stops before reaching end of track without further throttle action. In a later video demo 4), I'll demonstrate more aggressive braking action.

Above Demo 3. BellWe're running backwards with bell ringing. Aside from sounds, this video captures how realistically the loco comes to a stop, controlled by the decoder. I turn of the bell as the loco comes to rest. Finally, I use a magnetic wand (actually a magnet on a pencil) to turn off battery power and end the operating session.

Since S-CAB uses only 28 speed steps, I could not control a stop this precisely if Bill had not set realistic values for momentum. I'm only using the throttle to send a speed command. The decoder's configuration variables (CVs 3 and 4) determine how the loco responds and Bill's efforts have produced a good representation of prototype locomotive performance.

End of demo videos

Conclusion

This experience has me thinking about decoders and loco control from a new perspective. As a loco operator, all I can do is use available controls so that the loco does what I want, within the constraints of its design. I can't command a steam loco to perform like a sports car. A decoder should be configured to reproduce physical constraints of the loco model's full size prototype. It's not important whether the throttle uses 28 or 128 speed steps. I can whip the throttle to full speed with a flick of the thumb and the loco simply accelerates at a maximum rate allowed by the decoder. If I whip the throttle back to zero, the loco slows with prototypical realism if CV4 has been set appropriately. An elegant feature of Titan is it's capability to operate braking separately from throttle control. Just quickly move throttle to zero and use a function button to manage brakes. This capability is not unique among sound decoders, but braking sound effects are handled quite convincingly by Titan.

I acknowledge that many layouts are not big enough to operate steam locos operating in prototypical fashion, but keep in mind these videos show an S scale loco operating on six feet of track.

This is not journey's end, but I'm now convinced that Bill's persistence has been justified.

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Author

I'm a retired electrical engineer, but still spending more time on engineering than on my layout. These days, it's mostly about applying radio control and battery power on smaller scale layouts (HO, On3, On30)